Polyvinyl pyrrolidone (PVP) is a desirable laundry detergent ingredient because it: (a) inhibits dye transfer in the wash, thus protecting fabric colors; (b) scavenges chlorine from the wash water, thus reducing fabric bleaching by chlorine-containing wash water; and (c) prevents soils released from the washed fabrics from being redeposited on the fabric during the wash. However, it has been found that simply admixing PVP into a granular laundry detergent composition, particularly one containing citric acid, can cause flow problems and lumping and caking over time when the detergent composition is exposed to humid conditions. In the extreme case, the sticky PVP can cause the detergent composition to form into a brick-like mass inside the detergent carton.
It has now been found that this negative effect from admixing PVP into the detergent composition is reduced or eliminated through use of the present PVP additive.
Another advantage of this additive involves reducing the problems associated with handling PVP itself in bulk. Bulk quantities of the additive will tend to cake less and flow better than PVP by itself. It is thus more easily handled.
U.S. Pat. No. 3,868,336, Mazzola et al, issued Feb. 25, 1975, discloses a process for improving flowability of particulate detergents which include an oily detergent improver using a porous or finely divided flow-promoting agent.
U.S. Pat. No. 3,849,327,DiSalvo et al, issued Nov. 19, 1974, discloses the manufacture of a free-flowing particulate heavy duty synthetic detergent composition containing nonionic surfactant and anti-redeposition agent which can be polyvinyl alcohol or polyvinyl pyrrolidone.